There is disclosed a related art semiconductor device to perform phase compensation exceeding a delay time variable range of a first one of variable delay circuits by switching the first variable circuit into the second one when an output phase of the first variable circuit selected as a clock signal route differs from an output phase of the second variable circuit by one period.
In addition, there is disclosed another related art semiconductor device to prevent a phase comparator from excessively fluctuating following jitter by utilizing a majority circuit to decide the majority of phase comparison results.